1. Field of the Invention
The present invention relates to a twisted nematic (TN)-mode liquid crystal display (LCD) apparatus capable of improving gray scale display characteristics.
2. Description of the Related Art
In a prior art TN-mode LCD apparatus, twisted-mode type liquid crystal is inserted between two plane electrodes. In the prior art LCD apparatus, when the twisted angle of liquid crystal molecules in the liquid crystal is larger than a value around 270.degree., the tilt angle of liquid crystal molecules has an S shaped relationship to the voltage applied between the electrodes. Therefore, the transient orientation state of liquid crystal molecules during a rising voltage is different from that during a falling voltage. As a result, when an intermediate voltage between a high voltage and a low voltage is applied between the electrodes there are two orientation states of liquid crystal molecules mixed within one pixel. Thus, a large hysteresis is generated in the voltage-to-light transmittance characteristics, so that a gray scale display is impossible.